1. Field of the Invention
The present invention is generally related to crushing devices, and more particularly, but not by way of limitation, to an improved apparatus sealingly mounted to an airlock of an economizer ash hopper for breaking up ash clinkers and other deposits accumulated in the airlock to maintain passage of fly ash through the airlock.
2. Description of Related Art
Boilers employed in power plants are often heated by burning coal. The by-product of the combustion of coal is ash. This resultant ash is categorized as either bottom ash or fly ash. Bottom ash comprises accumulations of ash which are heavy enough to fall down through the boiler. The bottom ash is collected in a hopper positioned beneath the boiler. Fly ash comprises smaller particles of ash which are light enough to be carried up through the boiler with the flue gas.
A boiler is typically provided with several economizers which are positioned toward the downstream end of the boiler to utilize the hot flue gas in the boiler to preheat water returning from the turbines and condensers. As fly ash passes by the economizers, a portion of the ash deposits and accumulates on the outside of the economizers. To maintain the effectiveness of the economizers, the ash must be periodically removed. The removed deposits, which include ash clinkers, slag and other accumulated deposits, are collected in an economizer hopper positioned beneath the economizers.
The ash collected in the hopper is passed from the hopper to a pneumatic conveying system via an airlock. To pass the ash to the airlock, a vacuum is created in the airlock and an upper gate interposed between the hopper and the airlock is opened thereby causing the ash to be pulled into the airlock. When the airlock is filled, the upper gate is closed and the airlock is pressurized. A lower gate is then opened thereby forcing the ash from the airlock to the conveying system.
A V-shaped grating is disposed within the airlock to collect deposits of ash which are too large to be carried by the conveying system. After a period of time, the grating can become blocked by an accumulation of ash clinkers thereby preventing ash from passing from the airlock and causing the airlock to be rendered inoperable. Consequently, the ash clinkers accumulated on the grating must be frequently removed and the grating cleaned to ensure that the airlock continues to operate properly. However, such a task is time consuming and thus costly.
To this end, a need has long existed for an apparatus mounted to the airlock of an economizer ash hopper for breaking up ash clinkers accumulated on the grating disposed in the airlock thereby reducing the time and expense involved in cleaning the grating. It is to such an apparatus that the present invention is directed.